Homocysteine Analysis

Test Information

Elevations in plasma homocysteine levels may be associated with homocystinuria, cobalamin disorders, and vitamin B12 or folic acid deficiencies. Measurement of plasma homocysteine can be used to monitor patients undergoing treatment for Certain cobalamin disorders (CblC, CblD and CblE), which are characterized by hypotonia, failure to thrive, developmental delay and megaloblastic anemia and result in elevated homocysteine levels.

Turnaround Time

10 days

CPT Code(s)

83090

Cost

$100

Clinical Information

Homocysteine is a non-protein amino acid that is synthesized through the conversion of methionine. Elevations in plasma homocysteine levels may be associated with homocystinuria, cobalamin disorders (cblC, cblD, and cblE), and vitamin B12 or folic acid deficiencies.

Indications

The symptoms of homocystinuria include lens dislocation, osteoporosis, skeletal abnormalities such as genu valgum or a pectus deformity, thrombotic events, intellectual disability and psychiatric/behavioral disturbances. However, the phenotype is variable. Certain cobalamin disorders (CblC, CblD and CblE), which are characterized by hypotonia, failure to thrive, developmental delay and megaloblastic anemia, also result in elevated homocysteine levels. Measurement of plasma homocysteine can be used to monitor patients undergoing treatment for these conditions.

Methodology

Liquid chromatography-tandem mass spectrometry

Specimen Requirements

Plasma: at least 0.5 ml of plasma is required to perform this analysis. Peripheral blood should be collected in a sodium heparin tube. Plasma should be spun down, separated, and frozen within 4 hours of collection to prevent false elevations in homocysteine levels.

Transport Instructions

Plasma should be sent frozen, preferably on dry ice, via overnight delivery.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Analyte Analysis, Analytes and Biomarkers, Biochemical Testing, Newborn Screening Follow-Up
One Mother's Story

One Mother's Story

After a long three-year struggle trying to have children, our son, Charlie, was born on April 18, 2009. He was our miracle...perfect in every way! When Charlie was five days old, our pediatrician called to notify us that one of the numbers from the heel prick test was a bit high. We headed to the hospital that afternoon for more tests. I will never forget the following day. It was cool and crisp - not a cloud in the sky....

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